I can't think of a reason why you can't replace it with hose. I changed the last part of the cooler lines with hose because I wanted to bypass the radiator to it's own transmission cooler.

 

I replaced leaking sections of mine with hose.

 

Hose should be fine, but I wouldn't use regular worm-gear hose clamps. Spend the extra $$ and get the ones that use a bolt to tighten up. There isn't a lot of pressure in those lines, but there is pressure. And if the trans fluid can find a way, it will leak. Plus, I've had too many worm-gear clamps get over tightened and then you can never get them to hold right after. I don't trust them.

 

With all of that rust ...if I did use the worm type ...I'd use 2 of them and then get only stainless.
Agree that there is not a lot of pressure in the lines. On my 2000 4.7, I added an external trans fluid cooler, removing the internal radiator cooler form the circuit. I just used fuel line to route it as that's what the Dorman kit came with.
Don't overthink it.

 

Other than proximity to heat being an issue over time, hose should work fine. Hose sold as transmission line hose actually exists but fuel hose would probably work too. Obviously, vacuum line or non-reinforced hose should be avoided. You could probably use sections of scrap metal tubing in proximity to any heat source and then hose elsewhere.

I love hardware store type hacks that are equal to or better than an automobile OE's solution, especially when it comes at a fraction of the cost.

 

Thanks everyone, I'm glad to see the consensus is that rubber hose won't immediately burst and set my Jeep on fire.

Also I've never seen those fuel line style clamps before, but I'm going to pick up a bunch. They look like they could be useful elsewhere as well.

You could probably use sections of scrap metal tubing in proximity to any heat source and then hose elsewhere.

Not a bad idea.

Who came up with that sky-high $450 price at the parts store since that same Dorman 624-531 line is $73 plus shipping at Rockauto?? Maybe just a typo?

Ah, I see you've never been to PartSource or Canadian Tire. They may have been high when they set the price. Weed is legal here.

I found that same diagram online somewhere. As far as I can tell the Mopar Part 04799433AB or #8 on the diagram is a bushing, and then the steel line has a tube nut that screws into it. I don't think I can get outside one without paying stealership prices.

I like your idea of flaring the lines. Originally I studied the Dorman part and it looks like the ends of the lines are the same as the adapters I was going to pick up, but looking again with fresh eyes I'm qestioning that. I planned to use the adapters with the original tube nuts, but I could probably re-use the old lines and throw a bubble flare on them with a loaner flare too. I guess either way it's time to go spray penetrating oil while I wait for parts to arrive.

 

Who came up with that sky-high $450 price at the parts store since that same Dorman 624-531 line is $73 plus shipping at Rockauto?? Maybe just a typo?

https://www.rockauto.com/en/moreinfo.php?pk=8164396&cc=1420771&jsn=448&jsn=448

Regardless, everyone of those Dorman or Mopar trans/cooler lines on Rockauto have rubber hose attached or a place for it on one end towards the radiator/trans cooler.

If I'm going to cut a metal line and add rubber hose at the splice I'll use my flaring kit to put a slight flare on the end accepting the rubber hose. That way your clamps with be holding on the hose tight behind the flared metal line underneath. And I'll use 2 fuel injection clamps together on each hose connection since they're stronger than worm clamps while putting the screws on them on opposite sides.

I don't see a problem using rubber hose since you're keeping it away from the engine/exhaust on the frame rail or unibody. Just make sure you have it secured there good.

One thing I noticed in your photo is how rusted that line/nut is which goes in the higher fitting at the trans. If fixing the other rusted through parts of the line don't believe I'd leave that like it is. That is where the Dorman 624-531 or Mopar 52079375 line attaches which can be seen on page 007-620 of the 04 parts list.

Not sure where you'd place those fittings in your link and if you don't have a flaring tool many parts stores have loaner ones.

Know it's no fun to work on the lines where they attach to the transmission and of course it would be the hardest one to reach. Lots of rust cutter ahead of time for soaking. Good luck.

 

Am I correct in that the top metal line that goes to the bottom cooler fitting is the SEND and that the top cooler fitting that sends back to the bottom/lower metal line is the return?

 

Yes, the top line is the fluid leaving the trans, and the bottom line is the fluid heading back to the trans.